Secondary ion mass spectrometry (SIMS) with low energy sputtering is used to characterize ultrashallow-dopant profiles. Molecular ion sputtering species help reduce the mixing depth of the sputtering process and the broadening of the measured dopant distributions. The depth resolution of NO2+ and O-2(+) primary beams at 2 keV net acceleration and 55 degrees incidence angle to the sample are compared by the measurement of low energy ion implanted dopant distributions. The sputtering conditions result in a 380 eV/sputtering particle (normal to the sample surface) for NO2+, and a 570 eV/sputtering particle for O-2(+). Measurements of 1 and 2 keV BF2, as well as 5 keV As implants show trailing edge slopes of 2.6 nm/dec for the I keV BF2, and 5.5 nm/dec for arsenic. The pre-equilibrium region at the near-surface of the sample is shown to be similar for NO2 and O-2, indicating that chemical segregation effects of the nitrogen in the sample are not detrimental to the profile accuracy.